Means for holding engine-starting cartridges



April 5,`1955 T W. MILLNS 2,705,398

MEANS FOR HOLDING ENGINE-STARTING CARTRIDGES Filed Aug. 14, 1952 Zllbv QIUZLOP l .TINz/LLIZ/ idw @wrm Q .N c C non @f lll T @Qmmwmwi G \||||l .A g G l j Q .Mmfnrf l Nw Q Q N nited States Patent O i MEANS FR HOLDING ENGINE-STARTING CARTRIDGES Terence William Millns, London, England, assignor t Rotax Limited, London, England Application August 14, 1952, Serial No. 304,375

Claims priority, application Great Britain August 15, 1951 2 Claims. (Cl. 60-39.47)

For starting gas turbines or other engines, it is a usual practice to employ a cylindrical cartridge containing a solid propellant material which on tiring provides a quantity of gas at high pressure. Ordinarily the cartridge is inserted in a closely fitting cylindrical chamber, and is held in position by a removable cover on the outer end of the chamber. This arrangement has been found to be inconvenient as it is often ditiicult to withdraw the cartridge shell from the chamber after tiring.

The object of the present invention is to provide a cartridge securing means which is adapted to grip only an appropriately shaped nose piece on the forward end of the cartridge shell, as described, for example, in the concurrent application for patent, Serial No. 304,374.

The invention comprises a securing means having in combination a socket adapted to receive the forward end of a nose piece on the cartridge shell, and a clamping ring in screw-thread connection with the exterior of the socket, the ring and socket being adapted to grip between them at least one collar on the nose piece.

The invention also comprises the combination with the clamping ring, of a holder for the shell of the cartridge.

In the accompanying drawing:

Figure l is a sectional side elevation illustrating one embodiment of the invention, and Figure 2 is a fragmentary view illustrating a part not appearing in Figure 1.

Referring to the drawing, there is provided a socket a adapted to receive the nose piece b of the cartridge c. The socket may be formed on the turbine or engine casing d, or it may be made as a separate part adapted to be secured to the casing. On the socket a is formed an annular shoulder e adapted to serve as an abutment for a collar f formed on the exterior of the nose piece. In the example shown the shoulder e is chamfered for engagement with an annular under-cut on one face of the collar f. The exterior of the socket is screw threaded for engagement by an internally screw threaded and removable clamping ring g which is provided with an internal annular shoulder h having an inclined surface adapted to bear against the other and corresponding shaped side of the collar f of the nose piece, the arrangement being such that the said collar can be tightly gripped between the shoulders e, h on the socket and clamping ring.

The clamping ring may be adapted for manipulation in any convenient manner, but preferably it is slidably mounted within an annular housing formed on or secured to one end of a cagelike cylindrical holder j adapted to accommodate the shell c of the cartridge, the outer closed end of the holder being provided with a handle k for rotating the holder and clamping ring. Rotation of the ring g by the housing i is effected by a spline connection as indicated at m.

The arrangement is such that when the holder is detached from the engine a cartridge can be inserted in it. On replacing the holder, the nose piece of the cartridge is caused to enter the socket on the engine and the clamp- Patented Apr. 5, 1955 ing ring is engaged with the socket by rotation of the holder.

To secure the holder after the nose piece has been gripped, the forward end of the housing containing the clamping ring has formed on it a ring of ratchet-like teeth o adapted to engage complementary teeth on the engine casing. The interengagement of the teeth is permitted by the slidable freedom of the ring g in its housing and to ensure effective engagement of the teeth the ring is loaded by a spring p.

Also a trigger-like catch q is provided on the ring g as shown in Figure 2 for engaging a second collar r on the cartridge so that both cartridge and holder can be withdrawn together, the catch being provided with a iinger piece s and loaded by a spring t. After the cartridge has been fired, the holder together with the clamping ring and cartridge shell are detached from the socket, and the shell can then be easily removed from the holder` Assuming that the holder j has been detached from the engine, and that it is required to start the engine, a cartridge as cis iirst inserted into the holder until the catch q engages the second collar r on the cartridge. The holder containing the cartridge is now attached to the engine by causing the nose piece b of the cartridge to enter the socket a on the engine casing, and rotating the holder to screw the clamping ring g on to the socket until the irst mentioned collar is tightly gripped between the shoulders e, lz, on the socket and clamping ring, the holder being secured by engagement of its ratchetlike teeth o with the complementary teeth on the engine casing. To remove the holder after the cartridge has been tired, the holder is pulled outwardly to disengage the ratchet-like teeth, and is then rotated in the opposite direction to unscrew the clamping ring g whereupon the catch q is actuated to release the cartridge shell which can then be removed from the holder.

Having thus described my invention what I claim as new and desire to secure by Letters Patent is:

l. Means for securing in its tiring position on an engine casing, an engine-firing cartridge having a nose piece provided with at least one external collar, comprising in combination a socket for receiving the forward end of the nose piece, a clamping ring in screw thread connection with the exterior of the socket, the socket and clamping ring being provided with abutment surfaces between which the collar on the nose piece can be gripped, a rotatable cartridge holder which at one end contains the clamping ring and is provided with ratchet-like teeth for engaging complementary parts on the engine casing to secure the holder after the collar on the nose piece has been gripped between the said abutment surfaces, means interconnecting the clamping ring and cartridge holder so that the clamping ring is rotatable by but capable of sliding movement relatively to the cartridge holder, and spring means acting on the clamping ring to ensure effective engagement of the teeth on the holder with the complementary parts on the engine casing.

2. Means as claimed in claim l and having a pivotal cartridge-securing catch on the cartridge holder.

References Cited in the tile of this patent UNITED STATES PATENTS 1,328,088 Lutz Jan. 13, 1920 1,933,694 Allen et al Nov. 7, 1933 2,284,640 Cotfman June 2, 1942 FOREIGN PATENTS 579,074 France Oct. 9, 1924 

